Current plans to clean up the Chesapeake Bay could carry a price tag greater than $28 billion -- more than the budgets for NASA and the Commerce Department combined -- and most of that funding still hasn't been found, according to a panel studying the bay's financial support.

Exactly how much more money is needed? The nonprofit leaders and government representatives on the panel said they weren't sure. But in a report issued yesterday, they concluded that $15 billion would be a good start.

"Time is running out, and our last best chance to save [the bay] is before us," said former Virginia governor Gerald L. Baliles (D), who served as chairman for the group, the Chesapeake Bay Watershed Blue Ribbon Finance Panel.

The panel suggested creating a financing authority with $12 billion from the federal government and $3 billion from states in the bay's watershed, money that would be contributed over a six-year period.

This financing authority could then disburse the money as loans or grants to fund bay cleanup projects, such as improving sewage treatment plants or reducing agricultural pollution, the panel members said.

Baliles's group was commissioned last December by governors frustrated that little progress was being made toward a court-ordered deadline of cleaning up the bay by 2010.

The panel's task: Figure out what this cleanup would cost, and how it could be paid for.

Baliles said that turned out to be a tall order, since homes, sewage plants and other sources of pollution were constantly being built in the area and worsening the problem.

"I don't know how you do that in an area that's constantly growing, constantly changing," he said.

The panel's best guess was to add up the costs of each state's "Tributary Strategies" -- plans to clean up individual rivers and streams that bring pollution to the bay.

That bill: $28 billion in upfront costs, the report said. That's bigger than the annual budget for eight of the 15 federal Cabinet-level departments.

In addition, the panel found, the tributary strategies would require about $2.7 billion more to be spent annually on the bay.

Panel members said they were doubtful that all of the money would materialize.

"We couldn't possibly spend $28 billion between January 2005 and 2010," said John McNeil Wilkie, a Northern Virginia business executive on the panel.

Panel members noted the bay's dismal conditions: small populations of crabs and oysters, plus declining underwater grasses and growing stretches of algae that choke oxygen from plants and animals.

Given these problems, they said, they weren't worried about the ultimate cost of the plan.

"The cost of saving the bay will only get more expensive" as time goes on, said William C. Baker, president of the Chesapeake Bay Foundation and a member of the panel.

But the panel's suggestions face a difficult road. They will be presented to the Chesapeake Executive Council, a group of regional government leaders, in December. After that, the proposals might be taken up by state or federal legislators.

Howard Ernst, a U.S. Naval Academy professor who has criticized the slow pace of bay cleanup efforts, said he is worried that the proposals made yesterday would go nowhere.

"I know of nobody who believes that, in this climate . . . the federal government is prepared to come up with $12 billion in funding," Ernst said.

"Time is running out" on bay cleanup efforts, said former Virginia governor Gerald L. Baliles.